package com.lagou.mr.numcount;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;

import java.io.IOException;

public class NumSortDriver {
    public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException {
        // 1. 获取配置文件对象，获取job对象实例
        Configuration configuration = new Configuration();
        Job job = Job.getInstance(configuration);

        // 2. 指定程序jar的本地路径
        job.setJarByClass(NumSortDriver.class);

        // 3. 指定Mapper/Reducer类
        job.setMapperClass(NumSortMapper.class);
        job.setReducerClass(NumSortReducer.class);

        // 4. 指定Mapper输出的kv数据类型
        job.setMapOutputKeyClass(IntWritable.class);
        job.setMapOutputValueClass(NullWritable.class);

        // 5. 指定最终输出的kv数据类型
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(NullWritable.class);

        // 指定reduce task个数
        job.setNumReduceTasks(1);

        // 6. 指定job处理的原始数据路径
        FileInputFormat.setInputPaths(job, new Path("/tmp/numsort/input/"));

        // 7. 指定job输出结果路径
        FileOutputFormat.setOutputPath(job, new Path("/tmp/numsort/output/"));

        //8. 提交作业
        boolean result = job.waitForCompletion(true);
        System.exit(result ? 0 : 1);
    }
}
